Daily calorie requirements for adult males varies. For the typical 70 kilogram (154 pound) male:
· Sedentary 2,400-2,500
· Light activity 2700-3000
· Moderate activity 3,000-3.400
· Hard activity 3,400-4,500
· Extreme is up to 8,600 for certain occupations such as New England brick masons.
There is the famous Minnesota Starvation Experiment executed in the 1940s to study the effects of a starvation diet on young male adults: potential soldiers if you will. They were a selected group of motivated, healthy, intelligent, and well-adjusted young men. In short, not particularly representative of the general population.
The studies baseline diet was 3492 calories; during the semistarvation phase each person was allowed two meals a day that averaged a total intake of 1570 calories.
Body weight dropped 24% within 2 weeks and remained relatively constant throughout the 24-week semi-starvation period. This weight loss was accompanied by a marked increase in fat content of the body…There was a decrease in spontaneous activity that included intellectual pursuits. But there was no loss in mental capacity.
It is usually reported that during famines food becomes the central topfic of conversation and writing, and this was true for the Minnesota volunteers. They tended to become irritated when food service was slow, and were very annoyed if food was not served hot. During meals they ate slowly and deliberately, devoting total attention to the food and its consumption. They markedly increased the use of spices and salt, and abandoned any semblance of manner-always licking their dishes to obtain every last bit of food. Cookbooks, menus, and information bulletins on food production became intensely interesting, even for those who previously had little interest in dietetics or agriculture. Lewis F. Petrinovich The Cannibal Within.
Among the many conclusions from the study was the confirmation that prolonged semi-starvation produces significant increases in depression, hysteria and hypochondria. Many of the subjects experienced periods of severe emotional distress and depression.
There were extreme reactions to the psychological effects during the experiment including self-mutilation (one subject amputated three fingers of his hand with an axe, though the subject was unsure if he had done so intentionally or accidentally). Sexual interest was drastically reduced and the volunteers showed signs of social withdrawal and isolation. The participants reported a decline in concentration, comprehension and judgment capabilities, although the standardized tests administered showed no actual signs of diminished capacity.
There were marked declines in physiological processes indicative of decreases in each subject’s basal metabolic rate (the energy required by the body in a state of rest) and reflected in reduced body temperature, respiration and heart rate. Some of the subjects exhibited edema (swelling) in the extremities, presumably due to the massive quantities of water the participants consumed attempting to fill their stomachs during the starvation period. Wiki Report on Study
Of course these are the early stages. Eventually a tipping point is reached, and lathargia comes into play. Oddly enough the danger of rioting, and rebellion are more likely with populations that are hungry, but still have some calorie intake. Once a famine reaches an extended period the population becomes too lethargic. This can be seen in the early European revolutions where advances in aid and distribution limited the extent of food shortages, but made the State more susceptible to rebellion.
The effects of starvation:
Individuals experiencing starvation lose substantial fat and muscle mass as the body breaks down these tissues for energy and to keep functioning vital systems such as the nervous system and heart. Starvation, often leading to anemia, beriberi, pellagra, and scurvy. These diseases collectively can also cause diarrhea, skin rashes, edema, and heart failure.
Atrophy (wasting away) of the stomach weakens the perception of hunger, since the perception is controlled by the percentage of the stomach that is empty. Victims of starvation are often too weak to sense thirst, and therefore become dehydrated.
All movements become painful due to muscle atrophy and functioning. With a weakened body, diseases are commonplace. Fungi, for example, often grow under the esophagus, making swallowing unbearably painful.
The energy deficiency inherent in starvation causes fatigue and renders the victim more apathetic over time. As the starving person becomes too weak to move or even eat, his or her interaction with the surrounding world diminishes.
There is also an inability to fight diseases, and in females, irregular menstruation can occur. Wiki On Starvation [edited]